*Updates are underlined 

All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down. 

Unit 1 (Shut down) 
-Explosive sound and white smoke were confirmed after the big quake 
 occurred at 3:36 pm on March 12. It was assumed to be hydrogen explosion.
-At 3:37 pm on March 25, we started injecting freshwater to the reactor and 
 are now injecting fresh water by a motor driven pump powered by the 
 off-site transmission line.
 Water is currently injected at approx. 3.7 m3/h through reactor feed water 
 system piping arrangement. 
-We commenced injection of nitrogen gas into Primary Containment Vessel at 
 1:31 am on April 7.
-At 11:22 am on August 10, we started cyclic cooling for the water in the 
 spent fuel pool by an alternative cooling equipment of the Fuel Pool 
 Cooling and Filtering System. 

Unit 2 (Shut down) 
-At approximately 6:00 am on March 15, an abnormal noise began emanating 
 from nearby Pressure Suppression Chamber and the pressure within the 
 chamber decreased. 
-At 10:10 am on March 26, we started injecting freshwater to the reactor 
 and are now injecting fresh water by a motor driven pump powered by the 
 off-site transmission line. 
-At 2:59 pm on September 14, we started injecting water to the reactor 
 through core spray system water injection piping arrangement in addition 
 to the water injection through reactor feed water system piping 
 arrangement.
 Water is currently injected at approx. 3.1m3/h through reactor feed water 
 system piping arrangement, and at approx. 7.1 m3/h through core spray 
 system water injection piping arrangement.
-At 5:21 pm on May 31, we started cyclic cooling for the water in the spent 
 fuel pool by an alternative cooling equipment of the Fuel Pool Cooling and 
 Filtering System.
-At 8:06 pm on June 28, we started injecting nitrogen gas into the Primary 
 Containment Vessel. 

Unit 3 (Shut down) 
-Explosive sound and white smoke were confirmed at approximately 11:01 am 
 on March 14. It was assumed to be hydrogen explosion.
-At 6:02 pm on March 25, we started injecting fresh water to the reactor 
 and are now injecting fresh water by a motor driven pump powered by the 
 off-site transmission line.
-At 2:58 pm on September 1, we started water injection by core spray system 
 in addition to water injection by the reactor feed water system piping 
 arrangement. 
 Water is currently injected at approx. 2.1m3/h through reactor feed water 
 system piping arrangement, and at approx. 8.1 m3/h through core spray 
 system water injection piping arrangement.
-At 7:47 pm on June 30, we started cyclic cooling for the water in the 
 spent fuel pool by an alternative cooling equipment of the Fuel Pool 
 Cooling and Filtering System.
-At 8:01 pm on July 14, injection of nitrogen gas into the Primary 
 Containment Vessel started. 

Unit 4 (Outage due to regular inspection) 
-At around 6 am on March 15, we confirmed the explosive sound and the 
 sustained damage around the 5th floor rooftop area of Reactor Building.
-At 12:44 pm on July 31, we started cyclic cooling for the water in the 
 spent fuel pool by an alternative cooling equipment of the Fuel Pool 
 Cooling and Filtering System. 
-At 11:34 am on August 20, we started an operation of desalination 
 equipment in the spent fuel pool.
-At this moment, we don't think there is any reactor coolant leakage inside 
 the primary containment vessel. 

Unit 5 (Outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained.
-At 5:00 am on March 19, we started the Residual Heat Removal System Pump 
 in order to cool the spent fuel pool.
-At 2:30 pm on March 20, the reactor achieved cold shutdown.
-At 2:45 pm on July 15, we started the operation of the original Residual 
 Heat Removal System (System B) by its original seawater pump.
-At this time, we don't think there is any reactor coolant leakage inside 
 the primary containment vessel. 

Unit 6 (Outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained.
-At 10:14 pm on March 19, we started the Residual Heat Removal System Pump 
 of Unit 6 to cool down Spent Fuel Pool.
-At 7:27 pm on March 20, the reactor achieved cold shutdown. 
-At 2:33 pm on September 15, we started separately cooling the reactor 
 through the Residual Heat Removal System and the spent fuel pool through 
 Equipment Cooling Water System and Fuel Pool Cooling System.
-At this time, we don't think there is any reactor coolant leakage inside 
 the primary containment vessel. 

Others 
-At around 10 am on June 13, we started the operation of the circulating 
 seawater purification facility installed at the screen area of Unit 2 
 and 3.
-At 8 pm on June 17, we started operation of Water Treatment Facility 
 against the accumulated water. At 6:00 pm on July 2, we started the 
 circulating injection cooling to inject the water, which was treated by 
 the accumulated water treatment system, to the reactors through the buffer 
 tank.
-At 7:41 pm on August 19, we started treatment of accumulated water by 
 parallel operation of one line from the cesium adsorption instrument to 
 the decontamination instrument and the other treatment line of the cesium 
 adsorption instrument No.2. 
-At 2:06 pm on October 7, we started to spray purified accumulated water 
 brought from Unit 5 and 6 continually in order to prevent dust scattering 
 and potential fire outbreaks from the cut down trees.
-At 10:00 am on October 20, we started transferring the accumulated water 
 from the basement of turbine building of Unit 3 to the High Temperature 
 Incinerator Building of Central Radioactive Waste Treatment Facility.
-At 10:12 am on October 20, we started transferring the accumulated water 
 from the basement of turbine building of Unit 2 to the Process Main 
 Building of Central Radioactive Waste Treatment Facility.
-From 10 am to 11:30 am on October 24, we implemented transferring the 
 accumulated water brought from temporary tank to mega float.
-At around 11:30 am on October 24, as water leakage (about 20 litters) from 
 the pump gland at RO membrane unit was found, the Water Desalination 
 Facility was shutdown. Afterward, the water leakage was confirmed to be 
 stopped. Even though the Water Desalination Facility was shutdown, the 
 water injection into Reactors is continued. 
-At around 2 pm on October 23, TEPCO's employee found seemingly oil spill 
 outside the oil retaining wall of temporary oil tank for main transformer 
 in the power plant premise (Wild Bird Forest). The detail is under 
 investigation.